Abstract: A method for operating an internal combustion engine and a device for implementing the method may allow a catalytic converter diagnosis with a high degree of accuracy. At least one catalytic converter is positioned in the exhaust-gas region of the internal combustion engine, and a lambda sensor, which is configured as broadband lambda sensor, is positioned downstream from the catalytic converter or downstream from a section of the catalytic converter. The catalytic converter diagnosis is based on the evaluation of a measure for the oxygen storage capacity of the catalytic converter/within the catalytic converter. An at least approximately empty/filled oxygen reservoir of the catalytic converter is assumed. A change in the lambda setpoint value of the internal combustion engine to an excess air factor lambda that is greater than 1/less than 1 follows. Subsequently, a first change of the lambda signal is detected initially.

Abstract: A circuit configuration for operating a gas sensor is described, including a reference gas space in which an electrode is situated which is supplied with a reference gas pump current to maintain the concentration of the reference gas. A diagnostic system determines a concentration change of the reference gas via a change in the reference pump current and a time-based evaluation of the sensor signal of the gas sensor.

Abstract: The invention further relates to a method and a model for modeling a discharge phase of a nitrogen oxide (NOx)-storage catalytic converter (12?) of an internal combustion engine (1). The NOx-storage catalytic converter (12?) is subdivision into an oxygen (O2)-store and a nitrogen oxide (NOx)-store and a reducing agent mass flow (msrg) is determined which charges the O2-store and the NOx-store. To model a discharge phase of the NOx-storage catalytic converter (12?), the O2-store is modeled via a first integrator for oxygen (O2) and the NOx-store via a second integrator for nitrogen oxide (NOx) and the first integrator and the second integrator are charge proportionally with the reducing agent mass flow (msrg) in accordance with an apportioning factor determined in dependence upon the O2-store content (mo2sp) and the NOx-store content (mnosp) of the NOx-storage catalytic converter (12?).

Abstract: A method for controlling and regulating an electrical heating of a probe situated in the exhaust system of an internal combustion engine, a total heating power of the probe being set, and an actual temperature value of the probe being determined by measuring a characteristic parameter, e.g., a resistance. To prevent overheating of the probe ceramics, and therefore over-compensation of aging effects when using such a method, a rated heating power is determined by way of a program map as a function of operating points of the internal combustion engine; a control heating power is determined from the actual temperature value and a new setpoint value in a controller; and the total heating power is formed as the sum of the rated heating power and the control heating power. Moreover, due to this procedure, the regulating reserve of the controller is retained in wide ranges of the operating points. A cost advantage is yielded, because a measuring resistor and an analog-to-digital converter can be omitted.

Abstract: The invention relates to a method for operating a nitrogen oxide (NOx) storage catalytic converter (12?). During a first operating phase of the storage catalytic converter (12?), nitrogen oxides are stored and, during a second operating phase, stored nitrogen oxides are discharged from the converter (12?). The stored quantity of nitrogen oxides is determined during the first operating phase. In order to be able to determine start and end of the second operating phase as accurately as possible, a quantity, which characterizes the discharge quantity of nitrogen oxides, is determined during the second operating phase and compared to the stored quantity of nitrogen oxides determined during the first operating phase. With the comparison, a plausibility check and a calibration of the output signal of a nitrogen oxide (NOx) sensor (14?) can take place. The nitrogen oxide (NOx) sensor (14?) is disposed downstream of the storage catalytic converter (12?).

Abstract: A method for operating a nitrogen oxide (NOx) storage catalytic converter (12?) of an internal combustion engine (1) includes storing nitrogen oxides (NOx), which are generated by the engine (1), in a first operating phase in the NOx storage catalytic converter (12?). In a second operating phase, nitrogen oxides stored in the NOx storage catalytic converter (12?) are discharged from the NOx storage catalytic converter (12?). The start of the second operating phase is determined based on a nitrogen oxide (NOx) fill level (mnosp) of the NOx storage catalytic converter (12?) and the NOx fill level (mnosp) is modeled based on a nitrogen oxide (NOx) storing model (30). To be able to precisely and reliably determine the start and the end of the second operating phase, a first value of the nitrogen oxide (NOx) mass flow (msnonk_s) rearward of the NOx storage catalytic converter (12?) is detected and the NOx storing model (30) is corrected in dependence upon the detected first value.

Abstract: A method detects mass flows to the intake manifold of an internal combustion engine having a device for controlling the air supply to the intake manifold and having a sensor for detecting the intake manifold pressure and having a control apparatus for evaluating a trace of the intake manifold pressure. In the context of the method, when the internal combustion engine is switched off, the supply of air to the intake manifold is reduced in a predetermined manner and the trace of the intake manifold pressure, which adjusts thereupon, is evaluated for detecting the mass flows.

Abstract: A method for operating a catalytic converter arranged in the exhaust gas of an internal combustion engine. The composition of exhaust gas being controlled in front of the catalytic converter by adding a reducing agent that promotes the regeneration of the catalytic converter. The composition of the exhaust gas being detected with the aid of an exhaust-gas sensor positioned downstream from the catalytic converter. A time lag between the start of controlling the composition of the exhaust gas in front of the catalytic converter and the detection of a change in the composition after the catalytic converter are evaluated. In order to be able to determine the end of a regeneration phase of the catalytic converter in a safe and reliable manner, the gradient of an output signal of the exhaust-gas sensor is evaluated.

Abstract: A method of desulfurization of a ceramic storage medium for sulfur oxides and/or nitrogen oxides situated in a gas stream, in particular a storage device for nitrogen oxides or sulfur oxides situated in the exhaust gas stream of an internal combustion engine, is described, a mixture having a low oxygen concentration being established in the gas stream to release the stored sulfur oxides. A measuring signal is recorded by an oxygen probe positioned downstream from the storage medium in a gas stream flow direction, the curve of this measuring signal being used to determine the loading of the storage medium with sulfur oxides. This method allows determination of the need for desulfurization as a function of the loading of the storage medium with sulfur oxides, to monitor and control the progress of desulfurization initiated and to check on how complete the desulfurization that is concluded has been.

Abstract: A method and an electronic circuit for regenerating an electrical contact are provided in order to remedy the problem of electrical contacts becoming highly resistive over time. Electrical contacts become highly resistive over time, particularly when the contacts are thermally highly stressed and/or exposed to corrosive gases. To remedy this undesired effect and to reestablish the low resistance of the contacts, an electrical regenerating signal is applied to these contacts.

Abstract: An internal combustion engine for a motor vehicle. In the internal combustion engine, fuel is injected directly into a combustion chamber and is burned during an intake phase in a first mode of operation and during a compression phase in a second mode of operation. Exhaust gas formed by combustion may be sent to a catalytic converter. A controller may cause additional fuel to be injected following combustion in the second mode of operation. The controller may also cause the temperature of the exhaust gas to be measured in or downstream from the catalytic converter and compared with a threshold value.

Abstract: An internal combustion engine, especially for a motor vehicle, is described, which is provided with a catalytic converter which can be charged with hydrocarbons. The converting capability of the catalytic converter can be determined by a control apparatus. The converting capability of the catalytic converter is determined by the control apparatus by means of a combination of a passive and an active diagnostic method (27, 31).

Abstract: A method and a device for regulating the fuel/air ratio of an internal combustion engine having a first cylinder group, whose exhaust gases are guided through a first exhaust duct area, and having a second cylinder group, whose exhaust gases are guided through a second exhaust duct area. The first exhaust duct area contains a first catalytic portion and the second exhaust duct area contains a second catalytic portion. An exhaust gas analyzer probe, arranged upstream from the first catalytic portion, influences the fuel/air ratio of both the first and the second cylinder groups. A second exhaust gas analyzer probe, arranged downstream from the first catalytic portion, influences the fuel/air ratio of the first cylinder group, and a third exhaust gas analyzer probe, arranged downstream from the second catalytic portion, influences the fuel/air ratio of the second cylinder group. An additional exhaust gas analyzer probe upstream from the second catalytic portion may be eliminated.

Abstract: The present invention relates to a method for operating a catalytic converter (12) situated in the exhaust gas of an internal combustion engine (1), the composition of exhaust gas being controlled in front of the catalytic converter (12) by adding a reducing agent that promotes the regeneration of the catalytic converter (12), and the composition of the exhaust gas being detected with the aid of an exhaust-gas sensor (14) positioned downstream from the catalytic converter (12), and a time lag between the start of controlling the composition of the exhaust gas in front of the catalytic converter (12) and the detection of a change in the composition after the catalytic converter (12) being evaluated. In order to be able to determine the end of a regeneration phase (23, 33) of the catalytic converter (12) in a safe and reliable manner, it is proposed that the gradient of an output signal (31) of the exhaust-gas sensor (14) be evaluated.

Abstract: A method of desulfurization of a ceramic storage medium (10, 12) for sulfur oxides and/or nitrogen oxides situated in a gas stream, in particular a storage device for nitrogen oxides or sulfur oxides situated in the exhaust gas stream of an internal combustion engine is described, a mixture having a low oxygen concentration being established in the gas stream to release the stored sulfur oxides. A measuring signal is recorded by an oxygen probe (14) situated downstream from the storage medium (10, 12) in the direction of flow of the gas stream, the curve of this measuring signal being used to determine the loading of the storage medium (10, 12) with sulfur oxides. This method makes it possible to determine the need for desulfurization as a function of the loading of the storage medium (10, 12) with sulfur oxides, to monitor and control the progress of desulfurization initiated and to check on how complete the desulfurization that is concluded has been.

Abstract: An internal combustion engine, especially for a motor vehicle, is described, which is provided with a storage catalytic converter which can be loaded with and unloaded of nitrogen oxides. Several states of deterioration (points 13) of the storage catalytic converter can be determined by the control apparatus. A sulphur content of the fuel used can be determined by the control apparatus from sequential states of deterioration (points 13).

Abstract: A method for determining mass flows into the inlet manifold (3) of an internal combustion engine, with means (5, 6, 9), for controlling the air intake into the inlet manifold (5, 6, 9), means (4), for determining the inlet manifold pressure and means (11) for evaluating the inlet manifold pressure curve, is disclosed. Within the disclosed method, the air intake into the inlet manifold, on switching off the internal combustion engine, is reduced by a set amount and the curve for the inlet manifold pressure thus produced is evaluated for the estimation of the mass flows and a leak in the inlet manifold proven by an increased rate of pressure change.

Abstract: The invention relates to a method and a model for modeling a discharge phase of a nitrogen oxide (NOx)-storage catalytic converter (12′) of an internal combustion engine (1), especially of a motor vehicle. The NOx-storage catalytic converter (12′) is subdivided into an oxygen (O2)-store and a nitrogen oxide (NOx)-store and a reducing agent mass flow (msrg) is determined which charges the O2-store and the NOx-store. In order to model a discharge phase of the NOx-storage catalytic converter (12′) reliably and precisely and with the least possible complexity, the suggestion is made that the O2-store is modeled via a first integrator for oxygen (O2) and the NOx-store via a second integrator for nitrogen oxide (NOx) and the first integrator and the second integrator are charged proportionally with the reducing agent mass flow (msrg) in accordance with an apportioning factor.

Abstract: The invention relates to a method for operating a nitrogen oxide (NOx) storage catalytic converter (12′) of an internal combustion engine (1), especially of a motor vehicle, wherein, during a first operating phase of the storage catalytic converter (12′), nitrogen oxides are stored in the storage catalytic converter (12′) and, during a second operating phase, stored nitrogen oxides are discharged from the storage catalytic converter (12′) and, during the first operating phase, the stored quantity of nitrogen oxides is determined. In order to be able to determine start and end of the second operating phase as accurately as possible, it is suggested that a quantity, which characterizes the discharge quantity of nitrogen oxides, is determined during the second operating phase and is compared to the stored quantity of nitrogen oxides determined during the first operating phase.

Abstract: The invention relates to a method for operating a nitrogen oxide (NOx) storage catalytic converter (12′) of an internal combustion engine (1), especially of a motor vehicle. Nitrogen oxides (NOx), which are generated by the engine (1), are stored in a first operating phase in the NOx storage catalytic converter (12′) and, in a second operating phase, nitrogen oxides stored in the NOx storage catalytic converter (12′) are discharged from the NOx storage catalytic converter (12′). The start of the second operating phase is determined based on a nitrogen oxide (NOx) fill level (mnosp) of the NOx storage catalytic converter (12′) and the NOx fill level (mnosp) is modeled based on a nitrogen oxide (NOx) storing model (30).